Machine for sealing waxed paper bags



Sept. 25, 1945.

I A. B. M LAUCHLAN 2 ,385,583

MACHINE FOR SEALING WAXED PAPER BAGS Filed May 18, 1942 2 Sfieets-Sheet1 B. Mc.LAUCHLAN INVENTOR.

' Armmvsrs 1945- A. B. MCLAUCHLAN 2,385,583

MACHINE FOR SEALING WAXED PAPER BAGS Filed May 18, 1942 2 Sheets-Sheet 2ATTORNEYS Patented Sept; 25, 1945 MACHINE FOP SEALING WAX-ED PAPER mosArthur B. McLauchla-n, Salem, Oreg. Application May 18, 1942, Serial No.443,431

2 Claims.

This invention relates in general to devices for sealing the open endsof bags containing foodproducts, or other materials, where the sealingis to be accomplished by means of heat and pressure.

More specifically, this invention relates to ma-' chines for sealingwaxed paper bags containing food products, such as fresh berries and thelike, which are subjected to quickfreezing or sharp freezing," suchfreezing of the products for their preservation taking placeimmediatelyafter the bags have been completely sealed; and thisinvention relates in particular to the customary packaging of frozenfruits or other foods in which a waxed paper bag is placed as a liner inan open carton, then filled with a food product and sealed, after whichthe carton is closed and the entire package then subjected to thefreezing process and kept in a freezing temperature.

A number of devices and machines have been invented for heat-sealingwaxed paper bags used for such packages, but most of these are more orless complicated and are expensive to build and to maintain.

An object of this invention is to provide an improved sealing machinewhich will be comparatively simple in construction and require aminibetween the heat-Dressing elernents-for example,

when extra folds have been inadvertently made in the open bag ends to besealed-the extra thicknesses of the waxed paper clog and jam between theheat-pressing elements," damaging the package in question andtemporarily delaying further functioning of the device. An importantobject of my present invention, accordingly, is to avoid this difiicultyby providing heating-pressing elements of rollers which will beautomatically adjusted to accommodate extra thicknesses of paper withoutinterfering with their normal operation. This latter object I accomplishby employing heated rollers for the pressing elements and by having oneof the rollers adjustably springmounted.

Another problem encountered when heatingpressing elements are employedfor sealing such bags is involved in maintaining just the right amountof pressure, inasmuch as too great a pressure, especially if groovedsealing rollers are used, might damage or tear the waxed paper, whiletoo little pressure might not produce a perfect seal.

A further object of this invention is to provide adjusting means wherebythe sealing pressure may be modified as required and maintained atconstant predetermined, but adjustable, amount at all other times.

It is also desirable that the packages or cartons should be marked atthe time of sealing to indicate thelot or operators number, so thatshould any package later be found to be imperfectly sealed it can betraced for the purpose of ascertaining the probable cause of theimperfect sealing. A still further object therefore is to providesuitable meansfor marking the package or carton at the time of sealing.

These and other objects I accomplish by making my sealing machine in themanner hereinafter briefly described with reference to the accompanyingdrawings.

' In the drawings:

Fig. 1 is a side elevation of my improved machine with a waxed paper bagand its carton container shown in broken lines;

Fig. 2 is a front elevation of the same machine;

Fig. 3 is a fragmentary plan view of the forward end of the machine,with portions broken away for the sake of clarity and with a portionshown in plan section, the figure corresponding to the line 3--3 of Fig.2; and

Figs. 4A and 4B are fragmentary views of the meshing gears connected tothe heating pressing rollers, illustrating respectively the positions ofthe gears when-ordinary and when extra thicknesses of waxed paper arebeing sealed.

The machine includes a pair of horizontal plates comprising bottom plateIn and top plate II which are adjustably secured in parallel spacedrelation by a plurality of vertical rods l2. These rods preferably haveboth ends threaded, as shown at Figs. 1 and 2, and pairs of clampingnuts 12 are mounted on the threaded ends of the rods so as to enable therods and plates to'form a rigid but adjustable machine frame.

A pair of parallel guides 3 are supported on the bottom plate l0 andextend longitudinally through the machine for the purpose of guiding thecartons I! containing the paper bags to be sealed.

i'I'hese guides I 3 are adjustably secured to the bottom plate ID byscrews or bolts I I. (Fig. 3) ex- I tending through slots I 5 in plate I0 and thus enable the guides" to be placed further apart or closertogether to accommodate larger or smaller cartons. A conveyor belt l8,mounted on suitable rollers (not shown) and driven in any suitablemanner, conveys the filled cartons through 1. The forward ends of theguides l3 are flared outwardly as shown at l4 in Fig. 3 to facilitatethe proper positioning of the cartons on the conveyor belt.

.the machine from left to right as viewed in Fig.

bottom plate 60 and is connected at its lower end to suitable drivingmeans (not shown) by which rotation is imparted to the shaft 2i androller H. A gear 26 is attached to the shaft 2| above the hub 23.

w The other heat-pressing roller is secured at the bottom end of a shaft26 which is rotatably supported in a U-shaped bracket 21 extendingthrough a suitable slotted opening in the top plate II.

This U-shaped bracket 2'! has a pair of horizontal arms 28, one locatedabove and one below the plate II, which are mounted on a stub shaft 29supported in a hub 3|). Thus the U-shaped bracket 27, and therewith theshaft 26, are movable in a horizontal arc, thereby permitting theposition of the roller 20 to be varied with respect to the roller IS,the axis of the roller l9 being fixed. A

gear 25 is attached to the shaft 26 above the U- shaped bracket 21 insuch position as to mesh with the gear on the shaft 2 I.

In order to hold the roller 20 normally in a desired position withrespect to the companion roller I 3, I provide adjustable means atopposite sides of the bracket 21 as shown in Figs. 3 and 2. This meansincludes a stop screw 34, adjustably positioned in a lug 35, the purposeof which is to determine the minimum spacing between the rollers I havefound that, in sealing waxed paper bags,

especially when fluted or serrated rollers are used, it is best toprovide a slight spacing between the rollers-corresponding approximatelyto, but not exceeding, the thickness of two sheets of the waxed paper.Thus it will be noted in Fig, 2 that the rollers l9 and 20 are spacedapart approximately the thickness of the bag end l8 to be sealed, thatis, the thickness of two sheets of the waxed paper. This spacing is ofcourse adjustable by means of the stop screw 34. In the event that extrathicknesses of the waxed paper, due to any extra folds in-the' waxedpaper bag or to any other causes, are forced between theheatpressingrollers l9 and 20, the spring 3| will automatically permit the spacingbetween the rollers to be sufficiently increased to compensate for theextra thickness of the waxed paper, thus preventing any clogging orjamming of the paper between the rollers, and the adjusting screw 32 canbe set so as to provide just the right amount of spring pressuredesiredfor such extra thicknesses of the waxed paper. Even under-unusualcircumstances, however, the variation of the paper thickness will berelatively so small that the gears 24 and 25 (Figs. 2 and will continueto remain in mesh even though the spacing between the heat-pressingrollers is temporarily increased.

The shafts 2| and 26, to which the rollers l9 and 20 are attached, arehollowed out to permit heating elements to be inserted for the purposeof heating the pressing rollers. Electrical heating elements 36 areplaced in the hollowed shafts and are connected respectively to pairs ofring conductors 31 mounted at the top of each shaft. Wiper contact arms38, secured to a binding post 39, conduct electricaLcurrent, obtainedfrom a suitable source, to the heating elements in the usual manner.

Before sealing the tops of the waxed paper bags, it is desirable toexhaust most'of the air from the filled bags, and this is very simplydone in my machine by pressing down slightly on the bags on both sidesof the flattened wall surfaces which are to be sealed. For this purposeI provide a pair of pressing guides 40 extending longitudinally into themachine at the forward end. The for-. ward ends of these guides 4| areflared outwardly and upwardly, as shown in Figs. 2 and 3. I have foundit also desirable to have these guides 40 I inclined transverselyslightly from the horizontal,

as shown in Fig. 2, to conform more to the natural slope of the contentsin the bags at the-top. Furthermore, these guides are also adjustablymounted and are supported from the top plate II by rods 42 which havethreaded ends for the adjustable clamping nuts 42. This adjustablefeature enables cartons and bags of slightly different sizes to be usedin the machine. guides 40 not only exhaust most of the air from the topsof the bags before the sealing, but also aid in guiding and positioningthe flaps or tops of the side walls of the waxed paper bags for thepressing-heating-sealing operation performed by the rollers l9 and 20.

The cartons or containers H, in which the bags are placed before beingfilled, have customary lids 43 which are folded over in the usual mannerafter the sealing of the bags has been completed. While the bags arebeing sealed in the machine, the carton lids must be kept out of contactwith the heated. sealing rollers, and for this purpose, and also for thepurpose of placing identification marking on the carton lids, I providetwo pairs of horizontal lid guides 43 and 44, the upper pair 43 beingadjustably supported from the top plate II and the lower pair 44 beingadjustably supported by the bottom plate It). Both of these pairs ofcarton lid guides are secured to-rods 45 which have their opposite endsthreaded to accommodate the adjustable clamping nuts by which they areattached to the upper and lower plates of the machine frame. These pairsof guides thus hold the carton lid in horizontal position removed fromthe heat-pressing rollers while the sealing of the bags is taking place,and guide the carton lids to an identification stamping means which isprovided at the rear of the machine.

The stamping of the carton lids is performed 'by a stamping assemblyincluding a base member 41 (Fig. l) on which are mounted removable in-'dicia 48 for the purpose of placing any desired These wardly thereof.said guides acting to bring the top packers number, etc. Since cartonsin which frozen foods and other similar products are packaged generallyhave a waxed coating, the base member 47 is heated in order that heatmay be conducted to themarking indicia 48 to enable the identificationmarking to penetrate the waxed surface of the carton lid. This heatingis obtained through the medium of an electric heating element placed inthe base member 41 and connected to a suitable source of electriccurrent.

As the lid it of a carton passes over the heated indicia 48, a plungerplate 49, attached to the bottom of a plunger rod 50, presses the cartonlid down against the heated indicia 48 for a slight instant. The plungerrod 5ll'is actuated by a pivoted offset arm 52. The opposite or forwardend of the offset arm is arranged to be engaged by cam segments 55located on the top face of the gear 26. A spring 55 normally retains theplunger rod 50, and therewith the rear end of the offset arm 52, inraised position, and holds the forward end of the offset arm 52 againstthe top surface and cam elements of the rotating gear 24. The ofiset arm52 is pivotally mounted in a pair of supports 54 by means of a shaft 53.Should no marking of the carton be desired, the base member .41 and theplunger rod 50 can be removed from the machine.

I claim:

1. A machine for heat-sealing waxed paper bags including a pair of topand bottom plates, 9. pair of heating pressing. rollers mounted onvertical shafts and located below said top plate, the shaft for one ofsaid rollers supportedin a bearing on said top plate, the shaft for theother roller supported in a hinged bracket pivotally mounted on said topplate and adapted to swing in a horizontal plane, means for positioningsaid bracket and second mentioned shaft whereby to control the spacingbetween said rollers, said latter mentioned means including a positive,ad- J'ustable stop for maintaining a predetermined minimum spacingbetween said rollers and a resilient element normally holding saidbracket against said stop but allowing said minimum spacing to betemporarily increased to accommodate extra thickness of waxed paperpassing between said rollers, means for heating said rollers, means forrotating said rollers, a pair of longitudinally extending pressingguides located below said rollers, and extending forwardly and rearflapsof each bag into position in preparation for the heat sealing and tocause air to be exhausted from said bags by pressing down on said bagsprior to and during the sealing, said guides sup-v ported from said topplate, conveying means supported on said bottom plate for conveying saidbags through said pressing guides and pressing rollers, and means foradjusting the position of said top plate with respect to said bottomplate,

whereby bags of difierent size can be accommodated in said machinemerely by adjusting the position of said top plate with respect to said.bottom plate.

2. A machine for heat-sealing waxed paper bags comprising a pair of topand bottom plates, a pair of heating pressing rollers mounted onvertical shafts and located below said top plate, the shaft for oneoisaid rollers supported in a fixed bearing on said top plate, the shaftfor the other roller supported in a hinged U-shaped bracket pivotallymounted on said top plate and adapted to swing in a horizontal plane,means for positioning said bracket and second mentioned shaft whereby tocontrol the spacing between said rollers, said latter mentioned meansincluding a positive, adjustable stop for maintaining a predeterminedminimum spacing between said rollers and an adjustable spring normallyholding said bracket against said stop but allowing said mini-- mumspacing to be temporarily increased to accommodate extra thicknesses ofwaxed paper passing between said rollers, meansfor heating said rollers,means for rotating said rollers, a

pair of longitudinally extending pressing guides located below saidrollers, and extending forwardly and rearwardly thereof, said guidesacting to bring the top flaps of each bag into position in preparationfor the heat sealing and to cause air, to be exhausted from said bags bypressing down on said bags prior to and during the sealing, said guidesadiustably supported from said top plate. conveying means supported onsaid bottom plate for conveying said bags through said pressing guidesand pressing rollers. and means for adlusting the position of said topplate with respect to, said bottom plate, whereby bags of different sizecan be accommodated in said machine merely by adjusting the position ofsaid top plate with respect to said bottom plate.

ARTHUR B. McLAUCHLAN.

